1. Field of the Invention
The present invention relates to a feeding mechanism of an automatic pipe bending machine, more particularly one, which is equipped with two additional hydraulic cylinders, and an auxiliary fixing member capable of releaseably engaging a secured toothed locating rod plus connected with output rods of the additional hydraulic cylinders; thus, the feeding mechanism can feed a pipe with increased force output when the auxiliary fixing member is engaged with the locating rod, and when the additional hydraulic cylinders operate.
2. Brief Description of the Prior Art
Referring to FIGS. 10 to 13, a conventional automatic pipe bending machine 5 includes a main body 51, a feeding mechanism 52, and a bending mechanism comprised of both a fixed mold part 53 and a movable mold part 54.
Parallel guide rail 511 and rack 512 are secured on the main body 51. The feeding mechanism 52 is displaceable along the guide rail 511, and includes a first power source 521, a second power source 522, a holding tube 523 connected to the first power source 521, a transmission 524 connected to the second power source 522, and a gear 525 secured to an output shaft of the transmission 524 as well as engaged with the rack 512. To bend a pipe with the bending machine, the pipe is first secured to the holding tube 523, and the first and the second power sources 521 and 522 are actuated to make the holding tube 523 rotate, and the gear 525 roll along the rack 512 respectively. Thus, the feeding mechanism 52 is moved forwards, and in turns, the pipe is fed into the bending mechanism, and at the same time rotated together with the holding tube 523. Finally, the pipe is secured to the mold parts 53 and 54, and bent into a desired shape by means of angularly displacing the movable mold part 54 outwards.
Because the power source 522 makes the whole feeding mechanism 52 move forwards to feed a pipe with the help of the gear 525 and the rack 512 only, a lot of force will be exerted on the gear 525 and the rack 512 when the bending machine is in operation. Consequently, the gear 525 and the rack 512 are prone to wear, and the bending machine can't operate smoothly.